Heat transfer fin



Nov. 11, 1947. ESKRA 2,430,631

HEAT TRANSFER FIN Filed Sept. 11, 1944 IN VEN TOR.

650mm? IV. SKR/9 I HTTORNEYS,

Patented Nov. 11, 1947 HEAT TRANSFER FIN George N. Eskra, San Francisco, Calif., assignor to Pacific Metals Company, Ltd, San Francisco, Calif., a corporation of California Application September 11, 1944, Serial No. 553,555

2 Claims. (01. 257262) This invention relates to a heat transfer plate or fin for use on tubes or pipes.

Heat transfer fins used on pipes or tubes, as in refrigeration or heating systems or radiators are generally in the form of flat plates and are provided with openings for such pipes. The plates are in spaced relation on the tubes. Usually two or more pipes extend through each of the plates holding the latter aligned in a rowthereon, although some plates are apertured for merely a single pipe. Insofar as this invention is concerned it is applicable to plates having one or mor apertures for tubing or the like.

One of the objects of this invention is the provision of improved plate structure in which spacing lugs stamped from each plate will function to space the plates of adjacent pairs thereof in a row from each other either a greater or a lesser distance apart according to the end to end relation of alternate plates in the row.

Another object of the invention is the provision of identical plates and spacers stamped therefrom in which the spacers may be formed by a simpl die and which spacers on one plate of each adjacent pair thereof are adapted to cooperate with the openings from which the spacers of the other plate are struck to provide one spacing between plates While the same spacers On one plate of each adjacent pair are adapted to cooperate with the body of the other plate exclusive of the said openings in said other plate to provide a different spacing between adjacent plates in a row.

Other objects and advantages will appear in the description and drawings. h

In the drawings,

Fig. 1 is a plan view of one end of a row of plates on a pair of pipes, the latter being in section.

Fig. 2 is a fragmentary ,end elevational View of several plates in the row of plates of Fig. 1.

Fig. 3 is a fragmentary end elevational view of several plates in a row on pipes in which alternate plates as seen in Fig. 2 are reversed end for end to provide a closer spacing than that of Fig. 1.

Fig. 4 is a plan view of one end of a row of plates arranged as seen in Fig. 3, the pipes being in section.

Fig. 5 is a plan view of a single plate showing a modified structure for spacing-lugs, the latter being shown before bending to about a right angle relative to the body of the plate.

Fig. 6 is an end view of plates in a row, Which plates are completely formed from the blank of Fig. 5.

Fig. 7 is an end view of plates, similar to those shown in Figs. 5, 6, but with alternate plates reversed end for end from the position shown in Fi 5.

Before entering a detailed description of the plates whether of the form shown in Fig. 1 or in Fig. 5, it is pertinent to note that the spacers at diagonally opposite corners of the rectangular plates are identical in shape and position, while the spacers in longitudinal alignment with each other longitudinally of each plate, or those along each pair of adjacent edges of the plate, are the sam in contour but are differently arranged.

In detail, referring to Fig. 1, each plate I is formed with a pair of spacing lugs generally designated 2, 4, adjacent one edge thereof and with a pair of spacing lugs generally designated 3, 5, adjacent the opposite edge. Apertures are provided for pipe or pipes 6. All plates in a row are of the same shape and size and are identical with each other so that their edges are in alignment when aligned on the pipe. Where two or more pipes are used, which is the most common arrangement, the plates will not tend to rotate on the pipes or relative to each other, hence the spacers or spacing lugs need merely function to provide th proper spacing between plates.

The lugs-are stamped from each plate in the usual way and project from one side thereof whereby an opening is provided adjacent each lug corresponding in outline to the outline of the lug stamped therefrom. It is understood that each lug is integral with the plate along one edge of each such opening. Openings 8, ID are therefore respectively adjacent lugs 2, 4, while openings l, 9 are respectively adjacent lugs 3, 5.

The lugs 2 to 5 inclusive, are identical in shape and size. Lugs 2, 4 along one end edge of the plate are coplanar and lugs 33, 5 are coplanar, but the lugs 2, 4 have their flat sides in opposed relation to the sides of lugs 3, 5.

For purpose of description, the base of each spacing lug is the edge that is joined with the plate. From one end of said bas one edge ll of each lug extends slantingly upwardly and outwardly (Figs. 2, 3) relative to said base and the outermost edge l2 of each lug is parallel with the base. The edge l3 of each lug opposite the edge I l is at right angles to the base and a right angle shoulder is cut out of the lug between the adjacent ends of edges l2, l3 providing an edge l4 that is parallel with the base and one end of which joins an end of edge l3, and also providing an edge l5 parallel with edge l3 that joins one end of edge l2. An ear l6 bounded by edges ll, I2, I 5 is thus on each lug outwardly of the base portion I! of each lug.

Due to the inclination of edges ll of lugs 2, 4 which are on the opposed adjacent edges of said lugs, the latter are generally inclined edgewise toward each other, while on the other hand the inclined edges of lugs 3, 5 are on the opposite outer edges of said lugs; therefore said lugs gen erally incline edgewise outwardly from each other, or oppositely relative to lugs 2, 4. Thus when plates I are aligned on pipes 6 so that the corresponding lugs are also in alignment, it will 2,430, 3 be seen that the outermost end edges of the lugs on each plate will engage the body of the, plate adjacent thereto and the plates will be spaced apart the full lengths of the respective lugs (Fig. 2).

If, however, one of the plates of each adjacent pair is reversed end for end, or if alternateplates in the row are so reversed, then the lugs on said plates so reversed will be edgewise;inclinedioppositely to the plates adjacent thereto-land theflO ears IE will pass through the openings in the adjacent plates that are adjacent thereto r until shoulders 14 engage the body of the adjacent plate (Figs. 3, e). Inthis instancethe spacing between plates will be much less than before such 1 "reversal.

Generally 'rnost' requirements inany particular art, such as in the refrigeration art; are'metiby one or two standard spacings ofjthe heat trans- -ferffins, and with-my construction as *abovedescribed, a single *standard "plate "structure will "meet-either-oneor the otherof such requirements Without necessitating two *d-iflferent types "of rplates.

"In-Figs. 5', to Tisshown'aunodifieiilform or the invention in" which p'late "2 l is formed" with, apertures "for'pipe 6 the same 'asinthe 'case iof plate l,"-but'the'lugs"'22, Zfiand lugs 23,"25-that'posi- 'tionally correspond to -lugsf2, 4iand, 3,"5,are formed with parallel'side edges 3 I, 32ithat are 1 "inclined-relative tothe base "edge of'eachlug (-Fi'gsrfi, 7) These lugs do not have'fshoulders as in the previously described structurepbuteach terminates in an uterinost' edge -33'thatjs parallel with; the base edge ofeacli lug.

"Thelugs 22, *24'are edgewisehinclined toward EECITOthEI; while, lugs 23, '25are inclined'edgewise --away from each other. "Thei'edge'fil of each-lug -is{ the-edge that forms arr-acute iangle with plate "2], oraretheadjacent edges of lugs"22,"2fi and 40 r the opposite-outermost edgesof lugs; 23525.

When'pthe plates are '"ali'gned'on pipe with the correspondingly formed -lugsin alignment, the

outermost edgesii? ofeach-lug on each platewi'll "engage the-body-of the plateadjacent'thereto "GFig;- 6), but upon end to endweversal' of-one'of -eaBhadJ'aoent pair ofplates,':or* the end toiend '-'reversal of "alternate plates iniarowy ill bring the outermost endportions ofzthe-lugs"ina*position over the-openings from" which the. lugs that are-adjacent thereto on'the adjacentplate. "1T0 permit-partial projection of such tlugs'throrugh said openings, the openings are ma'de slightly wider than the logs with the added width "b eing *alongedges3i of said lugs as best seen:in"Fig."5, "as'at 34. "This added width allowsthelugs: to *pass through the openings upon said-reversal'as seen inFig. 7,t-hus'permitting alesser'spacirrg of plates than in' the arrangement of Figifi.

The structure of Figs. 1- to' l is preferablaandwo in allthe 'figures the thickness TOf the platesfas "shown is-greatly exaggerated for -clarity inas- --much as said. plates areusua-lly (if-relatively light gauge metal. v

It is to be understood thatthehrawing iarrd description 'aremerely illustrative ofthe invention and are not to be considered "restrictive thereof, inasmuch as it is'obvious' that any numberof spacing lugs maybeprovided,:and'certain variations in shape are possible.

I claim:

"1. A radiation-element including-a plurality" or atubes and rectangular elongated-parallel plates eo't corresponding :sizeandzshape' extending garound latdeast itwottubesmachrplate havingrflatipunched T out spacing lugs adjacent each corner projecting "from the sameside of each plate and in engagement with thei'platezadjacent thereto and with the fiat sides of each lug in planes substantially .normal to the plane of the plate, the outermost end edges of said lugs of each plate being straight Traridiima plane parallel to that of the plate, the

said outermost edges of the pair of lugs at one "end'of each plate' being ofiset in direction longiitu'dinallyythereofrelative to the base ends in direction toward a medial line extending longitusdinally: ofitheazplate and the outermost edges of thepairwof lugs at the opposite end of each plate being offset in direction longitudinally thereof relative to the base ends in direction away from said medial-line,=the-lugs-ononeplate of each such pair being formedand positioned to project-partially through the openings from which the I corresponding lugs on the adjacent plate v were punched i-n one position or the saida'dja- -=cent pair of plates relative to each other and-the said outermost edges-of thelugs of one plate' of 1 each adjacent pair being 5 formed and positioned to engage the solid portion of the other plate of each suchpair upon turning one -of the' plates oi said ad-jacent p'airl80 in. its plane relative to f thezsaid one position.

2. A radiation element includinga plurality of tubes -and rectangular elongated parallel plates or: corresponding size andshape extendin around at least two tubes,'each plate having fiat punched out-spacing: lugsadjacent-each corner projecting from the sarne 'side of each plate *andin engage- :ment With-the plate adjacent thereto and'with the flat sides of 'ea'ch luginplanessubstantially nor-malzto-the plane of the plate,- theoutermost en d edges'ofasaid lugs of each plate being straight saridiin a-plane parallel to that of the plate, the -sai d outermost edges of the pair of lugs at one -'-en'-d -of:=each 'plate-'beingoffset iii-"direction longi l tudinally thereof. relative tothe base-ends 1 in direction toward a-medial line extending longitudinally of the plate and the outermost edges of '..the pair'of lugs at the opposite'end- 'ofeach-plate :being -oi'lset in direction longitudinally thereof 1 relative to the base ends. in "direction away from said medial fline -the lugs 'on -one plate of each :lsuchpair will project partially through the openings from which -the correspo-nd-ing lugs on the adjacent plate were punched inone position of ithesaid'adjacent pair of plates relative to each other-and rthe said: outermost edges of the lugs ofizone plate: of each adjacent pairbeing formed and-positioned to engage thesolid portion of the :otherr plate: of each su'ch pair 7 upon turning one aofztherplateso'f said. adjacent -'pair -in its :plane a relative -to the said some position, and -a shoulder formed on each lug at a point intermerdiatez'its inner-'endand said outermost free edge providing .:a positive stop for -engagin the flat side of one of the plates of each-adjacent pair svvhen asaid 1plates.:are urged with the said lugs on one of: each adjacent. pair extending partially :throughthesai'dopenings.

1 GEORGE N. -ESKR'A.

REEEENGES vEITED The following references are of record'inthe V fi-le "of this patent: V

UNITED STATES PATENTS Number Name Date 1,920,357 ifilark AugLl; 1 933 i1-,-983,549 Krackowizer Dec. .11, 193.4 2,079,032 pitz May 4, 1937 

